This invention relates to an electronic whiteboard system and method, and more particularly to a novel eraser for use on an electronic whiteboard, a data filtering control system for use in conjunction with an electronic whiteboard and a method of filtering errant data associated with electronic whiteboards.
Electronic whiteboards are currently gaining favor in the market place because they provide for electronic recordation of all figures, words and characters handwritten on the whiteboard for later printout, review, and/or transmission. Typical electronic whiteboards include a resistive membrane stretched over a rigid substrate, an electronics module for determining the position of the instrument such as a pen used to write on the whiteboard and a computer for processing and storing the coordinates of the pen as it moves over the whiteboard. Examples of currently available electronic whiteboard systems include those marketed by Smart Technology, Inc. of Calgary, Canada and Microfield Graphics, Inc. of Beaverton, Oreg. See also U.S. Pat. Nos. 3,911,215; 4220,815; and 5,220,136.
Note that electronic whiteboard technology is different from copy whiteboards which are only capable of making copies of the material written on the whiteboard at discrete times during the presentation. In contrast, electronic whiteboards have the capability to display handwritten writing on the surface of the whiteboard and to also store digital data representing the handwritten writing during the complete presentation.
Currently available electronic whiteboards, however, suffer from a few serious short comings. For example, Smart Technology""s whiteboard system includes an erase function to eliminate or mark erased digital data but the user is required to select an erase mode, draw circle around the writing to be erased, and then select an erase command. The digital data representing the writing within the circle on the whiteboard is then digitally erased or marked. Still, the user must then use an eraser to physically erase the writing on the surface of the whiteboard. Obviously, this time consuming and awkward process is a serious departure from the normal way erasing occurs on a typical blackboard and thus the user must be provided with detailed instructions regarding how to properly erase the stored digital information, and the audience must patiently wait for the presenter to complete all the erasing functions before the presentation can resume.
One reason for this complex erasing methodology in the prior art is the fact that most erasers currently used are rectangular in shape and thus their area of coverage is dependent on the orientation of the eraser on the whiteboard. Another reason for this complex methodology is due to the fact that most erasers currently used are flat. Since the typical user may alternately presses lightly and then more firmly and/or rock the erasure from side to side during each erase stroke, it is difficult for the electronics to accurately detect where and how much of the eraser surface is actually touching the whiteboard.
Another shortcoming in current electronic whiteboards systems is the data integrity problems which occur due to inadvertent contacts with the whiteboard. For example, user may be writing with a pen in one hand on one part of the whiteboard and then place his or her hand on another portion of the whiteboard for balance. The whiteboard electronics may accurately record the pen movement but will also erroneously record the contact of the user""s hand with the whiteboard surface as a writing event. The same type of data corruption can occur due to electronic noise generated by outside influences beyond the control of the electronics portion of the whiteboard system. At printout or transmission, the corrupted data will thus not accurately match the actual writing on the whiteboard.
It is therefore an object of this invention to provide an improved electronic whiteboard system.
It is a further object of this invention to provide an improved whiteboard data processing and filtering method.
It is a further object of this invention to provide an improved method of erasing writing on a whiteboard.
It is a further object of this invention to provide such a system and such methods which allow the user to erase both the physical writing and erase or mark the electronic data representing the physical writing in an ergomonically sound manner.
It is a further object of this invention to provide such a system and such methods which allow the user to erase the physical writing and the electronic data representing the writing without the need to invoke an erase function, draw a circle around the information to be erased, invoke an erase command, and then physically erase the actual writing on the whiteboard.
It is a further object of this invention to provide such a system and such methods which automatically detect and then filter out inadvertent contacts with the whiteboard surface not properly attributable to writing or erasing by the user.
It is a further object of this invention to provide such a system and such methods which automatically eliminate erroneous data.
It is a further object of this invention to provide a novel eraser for use on an electronic whiteboard which provides positive position information.
It is a further object of this invention to provide such an eraser which is orientation independent.
This invention results from the realization that many of the data recording errors associated with writing and erasing actions on an electronic whiteboard can be eliminated by use of a circular and therefore orientation independent eraser with a central pointed protrusion which insures a positive initial contact of the eraser with the whiteboard; and/or also by the use of an electronic filter which detects and filters out data relating to contacts with the whiteboard not predictably associated with normal writing or erasing actions; and further that the filter constraints need to be changed and usually relaxed somewhat for erasing actions since people use an eraser in a fashion different than they use a writing instrument. This invention results from the further realization that the cumbersome prior art whiteboard erasing function wherein the user must first draw a circle around the writing to be erased in order for that writing to be electronically deleted can be eliminated by the use of the above described circular eraser with the central protrusion in conjunction with software or firmware which detects the occurrence of the user erasing the actual writing on the whiteboard and then simultaneously and automatically also erases or marks the stored electronic data representing the actual writing thereby rendering the electronic whiteboard more user friendly since writing and erasing, from the viewpoint of the user, occur just as if the user was writing on a chalkboard.
This invention features an electronic whiteboard system comprising: an electronic whiteboard; an eraser; means for storing data relating to information on and erased from the whiteboard; and means for simultaneously associating with the data an indication that the data is erased data as the eraser erases writing on the whiteboard relating to the data. The eraser may include an erasing surface with at least one convex area. The erasing surface is typically circular shaped with a radius r and the means for simultaneously associating includes means for marking as erased data all writing on the whiteboard under the erasure within r of the convex area.
This invention features a control system for an electronic whiteboard, the control system comprising: means for detecting and storing the location coordinates of an object on the whiteboard as it moves across the whiteboard; and filtering means, responsive to the means for detecting, including means for calculating the distance between first and second sequential location coordinates, means for determining the time interval between the first and second sequential location coordinates, means for comparing the calculated distance to a pre-established allowable maximum distance for the time interval, and means for rejecting the second location coordinate if the calculated distance is greater than the pre-established maximum allowable distance for the time interval to filter out inadvertent contacts with the whiteboard.
The filtering means may further include means for computing the change in velocity between three sequential coordinates, and means for rejecting the third velocity between three sequential coordinates, and means for rejecting the third coordinate if the change in velocity in velocity is greater than a pre-established maximum allowable change in velocity. The control system may further means for inputting the type of object to be moved across the whiteboard and means for changing the maximum allowable change in velocity depending on the type of object.
In the preferred embodiment, the control system further includes means for generating a first sound for a first type of object (i.e. a pen) and a second sound for a second type of object (i.e. an erasure) to provide positive feedback to the user of the whiteboard regarding the type of action occurring on the whiteboard.
The pre-established maximum allowable distance is usually between about 0.2 and 2 inches for a time interval of approximately 5 milliseconds. The pre-established maximum allowable change in velocity is typically about between 40 and 120 inches per second squared when the instrument type is a writing instrument and between about 320 and 960 inches per second squared when the instrument type is an erasing instrument.
The means for determining the location coordinates usually includes means for computing the Cartesian coordinates of the object. The means for calculating the distance includes means for computing the distance in the x direction and the distance in the y direction between the first and second sequential location coordinates and the pre-established maximum allowable distance then includes a maximum allowable x distance and a maximum allowable y distance.
The means for computing also includes means for calculating the change in velocity in the x and y directions. The pre-established allowable maximum change in velocity then includes a maximum allowable change in velocity in the x and y directions, and thus the means for rejecting the third coordinate includes means for excluding the third coordinate if either the maximum change in velocity in the x direction or the y direction is exceeded.
Stated another way, this invention features an electronic filter for an electronic whiteboard comprising: first rejection means, responsive to sequential contacts on the whiteboard which exceed a maximum allowable distance within an established time period, for rejecting at least one of the contacts; and second rejections means, responsive to sequential contacts on the whiteboard which exceed an established maximum allowable change in velocity, for rejecting at least one of the contacts. The control method for an electronic whiteboard of this invention features detecting the storing the location coordinates of an object on the whiteboard as it moves across the whiteboard; and filtering certain errant contacts with the whiteboard wherein filtering includes: calculating the distance between first and second sequential location coordinates, determining the time interval between the first and second sequential location coordinates, determining the time interval between the first and second sequential location coordinates, comparing the calculated distance to a pre-established allowable maximum distance for the time interval, and rejecting the second location coordinate if the calculated distance is greater than the pre-established maximum allowable distance for the time interval to filter out inadvertent contacts with the whiteboard.
Filtering may further include: computing the change in velocity between three sequential coordinates and rejecting the third coordinate if the change in velocity is greater than a pre-established maximum allowable change in velocity. Also added may be the step of inputting the type of object to be moved across the whiteboard, and then the maximum allowable change in velocity varies depending on the type of object. In a preferred embodiment, a first sound is generated for a first type of object type and a second sound is generated for a second type of object to provide positive feedback to the user of the whiteboard regarding the type of action occurring on the whiteboard.
An electronic filtering process according to this invention includes rejecting at least on of a plurality of sequential contacts on the whiteboard which exceed a maximum allowable distance between the contacts within an established time period and rejecting at least one of a plurality of sequential contacts on the whiteboard which exceed an established maximum allowable change in velocity between the contacts. This filtering process further includes the step of modifying the established maximum allowable change in velocity depending on the type of device contacting the whiteboard.
An electronic whiteboard system in accordance with this invention features a digitizer including a writing surface; control electronics for detecting and storing the location coordinates of an object on the whiteboard to keep a digital record of all writings and erasures on the whiteboard; and filter means for preventing the storage of digital data relating to contacts with the whiteboard not attributable to normal writing or erasing actions.